Technology abrogates the "finite" resources on the planet. As Monkeyboy said on another thread, agriculture has improved to the point where we need very few farmers in order to feed everybody. Similarly improved energy efficiency and the use of renewable energy (like solar power, which isn't going to run out anytime soon) means that the finite amount of oil and coal is not a limiting factor either. In short, living standards can rise without creating more resources. Technology is the key.

I think the "overpopulation" argument is overdone too. There is plenty of room for more people in many parts of the world. In the long run "overpopulation" is a self-correcting problem anyway. When it is impossible to feed new mouths, people will stop having babies (or worse, babies born will not live.)

And again, I don't see how overpopulation is related to "capitalism." "Capitalist" countries tend to have lower birthrates.